Rotary valve for an internal combustion engine

ABSTRACT

Rotary valves for internal combustion engines according to embodiments of the present invention comprise a conical valve portion with a first port of the rotary valve for feeding a fuel to the combustion chamber, respectively for an outlet of an exhaust from the combustion chamber, whereas the first port is located within a superficies surface of the conical valve portion; furthermore a cylindrical valve portion is arrange at a thick end of the conical valve portion, whereas a second port of the rotary valve for the fuel, respectively for the exhaust is located within a superficies surface of the cylindrical valve portion.

FIELD OF THE INVENTION

The present invention derives from the technical area of internal combustion engines; it relates to a rotary valve comprising a conical valve portion with a first port for feeding a fuel to the combustion chamber, respectively for an outlet of an exhaust from the combustion chamber, whereas the first port is located within a superficies surface of the conical valve portion.

BACKGROUND OF THE INVENTION

Internal combustion engines with rotary valves have been known since 1910 with the conception of the Burt McCollum's engine. There has been influence on this concept from Minerva, Panhard & Levassor and Mercedes producing this combustion engine—patented by Knight—till 1939. Due to sealing problems the concept of the Burt McCollum engine had to be abandoned. Conventional cylinder heads with oscillating valves have the well-known disadvantages of offering restricted performance and discontinuous supply of fuel-mixture. Major drawbacks result from the valves, the ignition and the sealings, that need constant surveillance and maintenance with the involved costs.

The EP1304449B1 reveals a valve drive for a rotary valve of an internal combustion engine; the rotary valve according to this invention has a conical valve portion with flow through channel passing this conical valve portion generally perpendicular to a rotation axis of the rotary valve.

The U.S. Pat. No. 2,245,743 discloses a rotary valve assembly for internal combustion engines with a head of a valve member mounted into rotate about its axis in a coacting conical surface of the head, while its stem is carried by two roller bearings. Major drawbacks result from the valves being exposed with their frontal surface to the combustion chamber and thus being exposed to heavy pressure and thermal loads. Another drawback is to be seen in the conical surface of the valve that serves as passageway and as slide bearing without clearly separating these two functions.

The U.S. Pat. No. 3,362,391 reveals rotary valves for intake and exhaust in an internal two or four stroke combustion engine. A rotary valve of that kind is outwardly inclined and comprises a tapered cone-shaped tube having an enlarged gas induction and/or exhaust portion. Furthermore, the valves have a reduced drive portion and an intermediate port portion. All of these portions are integrally formed of one body with an interior bore. Especially the gas induction and/or exhaust portion is adapted to receive a manifold tube, namely a gas induction tube or a gas exhaust tube. Recapitulating, from this prior art document a rotary valve is known, comprising a conical valve portion with a port for feeding a fuel to the combustion chamber, respectively for an outlet of an exhaust from the combustion chamber, whereas the port is located within a superficies surface of the conical valve portion. Major drawbacks of said prior art valves are seen in the tubular embodiment with an axial flow through channel in the whole valve arrangement for the gas induction, respectively the exhaust. Not only the cone-shaped valve portion is discharge with gas/exhaust, but also the rotary tubular cylindrical end portion fixed to that cone-shaped valve portion is exposed to the gas/exhaust.

SUMMARY OF THE INVENTION

A rotary valve is disclosed for two or four stroke internal combustion engines which overcomes the above-mentioned disadvantages while offering advantages for the construction, the tightness against uncontrollable gas losses and the ease of operation.

According to at least one embodiment of the present invention a rotary valve for an internal combustion engine is provided comprising a conical valve portion with a first port for feeding a fuel to the combustion chamber, respectively for an outlet of an exhaust from the combustion chamber, whereas the first port is located within a superficies surface of the conical valve portion and whereas a cylindrical valve portion is arranged at a thick end of the conical valve portion with a second port for the fuel, respectively for the exhaust, which is located within a superficies surface of said cylindrical valve portion.

The valve port in the conical valve portion to a cylinder of the engine is taken apart from a second valve port located in an adjacent cylindrical valve portion. Due to that separation of each of the valve portions, namely the conical valve portion and the cylindrical valve portion, it is easy to seal separately each portion at one port at a superficies surface against cylinder head housing. It has to be emphasized that the two separated valve ports close directly the channels to and from the valve by rotating, whereas the operational dependability is significantly increased comparing to the prior art devices. This means that the requirements regarding tightness and cooling are sufficiently designed for mass production.

In at least one preferred embodiment of the invention a flow channel is arranged between the first port of the rotary valve in the conical valve portion and the second port in the cylindrical valve portion, which flow channel is a slant or curved flow channel that crosses a rotation axis of the rotary valve. Furthermore, the conical valve portion is located adjacent to a combustion chamber, which allows an optimal sealing against the combustion chamber in view of different dilatation of the rotary valve and the enclosing cylinder head housing.

A further advantageous embodiment of the invention provides a first sealing located at a thin end of the conical valve portion and a second sealing located close to a transition zone between the conical valve potion and the cylindrical valve portion, whereas the first port of the conical valve portion is located between the first sealing and the second sealing. Further, a third sealing is located at an end of the cylindrical valve portion that is turned away from the conical valve portion, whereas the second port of the cylindrical valve portion is located between the second sealing and the third sealing. To the best advantage at least one of the first, the second or the third sealing is a lamellar labyrinth sealing.

A further advantageous embodiment shows a low friction coating on the rotary valve, which seals the rotary valve against the cylinder head housing and the combustion chamber; by using a low friction coating like a diamond coating no further sealing is needed.

For the sake of a reduced overall height of the cylinder head housing the rotation axis of each rotary valve is arranged perpendicular to a cylinder axis of a cylinder that is served by said rotary valve. For the ease of operation at least a first and a second rotary valve are arranged in a cylinder head of a cylinder, whereas said rotary valves are preferably mounted parallel to each other with the same alignment.

Further preferred embodiments of the invention show cavities in the conical valve portion, the cylindrical valve portion or the cylinder head.

BRIEF DESCRIPTION OF THE DRAWINGS

The herein described embodiments of the invention will be more fully understood from the detailed description below and the accompanying drawings, which should not be considered limiting the invention described in the appended claims:

FIG. 1 shows a longitudinal section through an internal combustion engine with a rotary valve according to at least one embodiment of the invention;

FIG. 2 shows in a longitudinal section the rotary valve with a coating as sealing;

FIG. 3 shows in a longitudinal section a further embodiment of the rotary valve according to at least one embodiment of the invention with cavities;

FIG. 4 shows a further longitudinal section of the rotary valve with cavities;

FIG. 5 shows the rotary valve in a cylinder head;

DETAILED DESCRIPTION OF THE FIGURES

In FIG. 1 a rotary valve according to at least one embodiment of the invention is shown in its operational position in a cylinder head 18 of an internal combustion engine. Although this rotary valve is combined with an internal combustion engine, the invention is not indented to be reduced to this arrangement; it is also possible to use the rotary valve according to the invention in any other control or regulation cycle for fluids.

Under the cylinder head 18 a cylinder 12 with a piston 13 and a combustion chamber 2 is shown that is served by the rotary valve. The rotary valve comprises a conical valve portion 1 and a cylindrical valve portion 8 that is arranged at the thick end of the conical valve portion 1. The conical valve portion 1 shows at its superficies surface 3 a first port 6 of the rotary valve and a second port 7 of this rotary valve is located at a superficies surface 5 of the cylindrical valve portion 8. Between these first and second ports 6, 7 a slant or curved flow channel 9 is installed. Due to this slant or curved flow channel through the rotary valve the first and second ports 6, 7 are taken apart to the conical valve portion 1, respectively the cylindrical valve portion 8, whereas the slant or curved flow channel crosses a rotation axis of the rotary valve. This inventive arrangement allows for the first time an easy handling of a rotary valve especially regarding sealing.

A first sealing 11 a is located adjacent to a second bearing 14 b at a thin end of the conical valve portion 1 of the rotary valve and a second sealing is arranged close to a transition zone between the conical valve portion 1 and the cylindrical valve portion 8. The first port 6 is accordingly located between these first and second sealings 11 a, 11 b. The second port 7 is framed by the second sealing 11 b and a further third sealing 11 c that is installed at the thick end of the cylindrical valve portion 8 turned away from the conical valve portion 1.

Adjacent to the conical valve portion 1 a valve drive 15 and a first bearing 14 a is installed. Characterizing for embodiments of the invention is further the angle between the rotation axis 10 of the rotary valve and a cylinder axis 19 of the cylinder 12, namely the rotation axis 10 and the cylinder axis 19 are arranged perpendicular to the each other, that means that the rotary valve is not outwardly inclined and the overall height of the new rotary valve assembly is reasonably smaller as known from prior art.

FIG. 2 shows a further embodiment of the invention. The rotary valve according to this exposition does not need any first, second or third sealing 11 a, 11 b, 11 c, as shown in relation to FIG. 1. Here in FIG. 2 the rotary valve is coated with a low friction coating that allows the use of the rotary valve without any losses regarding the sealing. Such a low friction coating can be provided by a diamond coating that is used in formula one engines for sealing between pistons and cylinders.

The further embodiment of the invention shown in FIG. 3 reveals a cavity 17 a in the conical valve portion 1 and a cavity 17 b in the cylindrical valve portion 8. These cavities 17 serve as compensation volumes regarding different heat expansions of all elements of the rotary valve in the cylinder head 18 (FIG. 1). This compensation can further be improved by filling the cavities 17 with thermodynamic acting filler like a thermal wax. In this embodiment the rotary valve is shown with the first, second and third sealing 11 a, 11 b, 11 c. As mentioned above the sealing can also be provided by low friction coating 16; this further embodiment is shown in FIG. 4.

In FIG. 5 the position of two rotary valves both—serving one and the same cylinder 12—in a cylinder head 18 is shown. These rotary valves have the same alignment, which means that these rotary valves are driven by valve drive on the same side of their respective rotation axis. Furthermore, the housing of the cylinder head 18 comprises also cavities 17 with the same thermal function as the cavities in the conical valve portion 1 and the cylindrical valve portion 8 of the rotary valve. Accordingly it is also possible to fill these cavities in the cylinder head 18 housing with thermodynamic filler like the thermal wax mention above.

Further possible embodiments of the invention are covered by the claims and therefore comprised by this present application.

References  1 conical valve portion  2 combustion chamber  3 superficies surface of the conical valve portion  4 thick end of the conical valve portion  5 superficies surface of the cylindrical valve   portion  6 first port of the rotary valve  7 second port of the rotary valve  8 cylindrical valve portion  9 flow channel 10 rotation axis 11a, b, c first, second, third sealing 12 cylinder 13 piston 14a, b, c first, second, third bearing 15 valve drive 16 coating 17a, b cavity 18 cylinder head 19 cylinder axis 

1. A rotary valve for an internal combustion engine comprising: a conical valve portion including a first port of the rotary valve for feeding a fuel to a combustion chamber and for an outlet of exhaust from the combustion chamber, wherein the first port is located at a superficies surface of the conical valve portion and adjacent to the combustion chamber; and a cylindrical valve portion arranged at a thick end of the conical valve portion, wherein a second port of the rotary valve for the fuel and for the exhaust is located at a superficies surface of the cylindrical valve portion.
 2. The rotary valve according to claim 1, wherein a flow channel is arranged between the first port of the conical valve portion and the second port of the cylindrical valve portion, whereas the flow channel is a slant or curved flow channel that crosses a rotation axis of the rotary valve.
 3. (canceled)
 4. The rotary valve according to claim 1 wherein a first sealing is located at a thin end of the conical valve portion and a second sealing is located close to a transition zone between the conical valve potion and the cylindrical valve portion, and wherein the first port is located between the first sealing and the second sealing.
 5. The rotary valve according to claim 4, wherein a third sealing is located at an end of the cylindrical valve portion that is turned away from the conical valve portion, whereas the second port is located between the second sealing and the third sealing.
 6. The rotary valve according to claim 5 wherein at least one of the first, the second or the third sealing is a lamellar labyrinth sealing.
 7. The rotary valve according to claim 1 wherein a rotation axis of the rotary valve is arranged perpendicular to a cylinder axis of a cylinder that is served by the rotary valve.
 8. The rotary valve according to claim 1, wherein rotary valve is a first rotary valve arranged in a cylinder head of a cylinder along with a second rotary valve, and wherein said first and second rotary valves are mounted parallel to each other with the same alignment.
 9. The rotary valve according to claim 1, wherein the conical valve portion includes at least one closed conical valve portion cavity for a thermodynamic compensation of different temperature coefficients.
 10. The rotary valve according to claim 9, wherein the conical valve portion cavity is filled with a thermodynamic acting filler.
 11. The rotary valve according to claim 10 wherein the thermodynamic acting filler is a thermal wax comprising nitrogen gas.
 12. The rotary valve according to claim 1, wherein the cylindrical valve portion includes at least one closed cylindrical valve portion cavity for a thermodynamic compensation of different temperature coefficients.
 13. The rotary valve according to claim 12, wherein the cylindrical valve portion cavity is filled with a thermodynamic acting filler.
 14. The rotary valve according to claim 13, wherein the thermodynamic acting filler is a thermal wax comprising nitrogen gas.
 15. The rotary valve according to claim 8, wherein the cylinder head for the rotary valve exhibits at least one closed cylinder head cavity for a thermodynamic compensation of different temperature coefficients.
 16. The rotary valve according to claim 15, wherein the cylinder head cavity is filled with a thermodynamic acting filler.
 17. The rotary valve according to claim 16 wherein the thermodynamic acting filler is a thermal wax comprising nitrogen gas.
 18. The rotary valve according to claim 1 wherein the conical valve portion and/or the cylindrical valve portion are/is coated with a low friction coating.
 19. The rotary valve according to claim 18 wherein the low friction coating is a diamond coating. 